A historical literature review of coronary microvascular obstruction and intra-myocardial hemorrhage as functional/structural phenomena

The analysis of experimental data demonstrates that platelets and neutrophils are involved in the no-reflow phenomenon,also known as microvascular obstruction(MVO).However,studies performed in the isolated perfused hearts subjected to ischemia/reperfusion(I/R)do not suggest the involvement of microembolization and microthrombi in this phenomenon.The intracoronary administration of alteplase has been found to have no effect on the occurrence of MVO in patients with acute myocardial infarction.Consequently,the major events preceding the appearance of MVO in coronary arteries are independent of microthrombi,platelets,and neutrophils.Endothelial cells appear to be the target where ischemia can disrupt the endothelium-dependent vasodilation of coronary arteries.However,reperfusion triggers more pronounced damage,possibly mediated by pyroptosis.MVO and intra-myocardial hemorrhage contribute to the adverse post-infarction myocardial remodeling.Therefore,pharmacological agents used to treat MVO should prevent endothelial injury and induce relaxation of smooth muscles.Ischemic conditioning protocols have been shown to prevent MVO,with L-type Ca2+channel blockers appearing the most effective in treating MVO.

The effect of an adaptation to hypoxia on cardiac tolerance to ischemia/reperfusion

The acute myocardial infarction(AMI)and sudden cardiac death(SCD),both associated with acute cardiac ischemia,are one of the leading causes of adult death in economically developed countries.The development of new approaches for the treatment and prevention of AMI and SCD remains the highest priority for medicine.A study on the cardiovascular effects of chronic hypoxia(CH)may contribute to the development of these methods.Chronic hypoxia exerts both positive and adverse effects.The positive effects are the infarct-reducing,vasoprotective,and antiarrhythmic effects,which can lead to the improvement of cardiac contractility in reperfusion.The adverse effects are pulmonary hypertension and right ventricular hypertrophy.This review presents a comprehensive overview of how CH enhances cardiac tolerance to ischemia/reperfusion.It is an in-depth analysis of the published data on the underlying mechanisms,which can lead to future development of the cardioprotective effect of CH.A better understanding of the CH-activated protective signaling pathways may contribute to new therapeutic approaches in an increase of cardiac tolerance to ischemia/reperfusion.

Frequency of C825T G protein β3 subunit gene polymorphism and its association with obesity in the Kyrgyz population

Objective:To examine the frequency of C825T G protein β3 subunit gene polymorphism and its association with obesity of ethnic Kyrgyz.Methods:The study enrolled 210 people,89 patients(35 females,54 males)with obesity(BMI≥30 kg/m2)and 121 practically healthy patients(38 females,83 males)with normal body weight and no signs of type 2 diabetes(group of control),who were not observed before by a cardiologist.The blood pressure,anthropometry,glucose and lipid profile were examined among all subjects.Genomic DNA was extracted from peripheral blood cells.G proteinβ3 subunit C825T polymorphism was determined by polymerase chain reaction(PCR).Results:TT and CT genotypes carriers were grouped together in one group because the TT genotype was rare.CT+TT genotype frequency in the group with obesity made 0.72 and was significantly higher than that in the control group-0.52(χ2-8.44;P=0.004;odds ratio-2.55;95%CI 1.31-4.23).The statistical analysis revealed that hypertension(45%vs.31.3%,P=0.049)and obesity(51.2%vs.30%,P<0.01)occurred significantly more often in CT+TT genotype carriers than in the CC homozygotes.The results of the multivariate logistic regression analysis showed that the presence of 825T allele(exp β-2.89;95%CI 1.25-6.7;P=0.013),along with the occasional consumption of vegetables(exp β-3.47;95%CI 1.52-7.94;P=0.003)was the significant risk factor for obesity,regardless of gender,age and level of physical activity.In the construction of the similar regression model for hypertension,the statistically significant role of 825T allele was lost after adjustment for obesity as an independent variable.Conclusion:G protein β3 subunit gene C825T allele in the Kyrgyz ethnic group has an association with obesity.